


Just Two Sisters

by StarlightBellona



Category: Supergirl (TV 2015)
Genre: Blow Jobs, Breast Fucking, Clothed Sex, Come Marking, Come Shot, Come Swallowing, Comfort Sex, Don't Like Don't Read, Explicit Sexual Content, F/F, Forbidden, Girl Penis, Girl Penis Kara Danvers, Hand Jobs, Missing Scene, Multiple Orgasms, Oral Sex, Plot What Plot/Porn Without Plot, Pseudo-Incest, Shameless Smut, Smut, Step-Sibling Incest, Taboo, Vaginal Sex
Language: English
Status: Completed
Published: 2019-05-14
Updated: 2019-05-14
Packaged: 2020-03-05 15:28:26
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,696
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18831439
Author URL: https://archiveofourown.org/users/StarlightBellona/pseuds/StarlightBellona
Summary: Kara is jealous that Alex went on a fake date with Maxwell Lord. She hesitantly gives in as Alex seeks to reassure and comfort her.Takes place at the end of Season 1, Episode 10.





	Just Two Sisters

**Author's Note:**

> My first fic for this pairing. Not sure if I'll do anymore smut with these two but inspiration hit and I had to write it. Hope someone out there enjoys it!

Another stressful day ended with Kara snuggling up next to Alex on the couch. Kara still wore her Supergirl outfit, happy to have someone she could relax around like nobody else, free to be herself. They grabbed slices of lukewarm cheese pizza, content enough to unload some stress from the day through a quick chat. It was always nice for Kara when they had these talks, but when Alex mentioned going on a fake date with Maxwell Lord, a pang of anger flared up inside Kara’s chest.

She tried to push it down, reminding herself that he held no power or sway over Alex, but as the night wore on, it kept resurfacing in her mind, and each time her blood wanted to boil. After their episode of Game of Thrones had finished, Kara brought it up again without really thinking through what she wanted to say. She didn’t really understand it—all she knew was that the thought of Alex dressing up all sexy for Maxwell Lord pissed her right off.

“Alex, I know you can take care of yourself, but I don’t want you alone with that man ever again,” Kara huffed. Her fists were clenched tight. She shook them loose, though she still wanted to destroy something—or someone.

“I told you, Kara. I’ve dealt with guys like him for years. He’s not worth worrying yourself over,” Alex said, smiling reassuringly at Kara. It didn’t ease her frustrations at all.

“That’s not it. I just—I hate the thought of you dressed up for him. He doesn’t deserve to see you like that,” Kara said, turning her head away from her sister.

“Kara, are you… jealous?” Alex teased, amusement evident in the tone of her voice.

“No! Why would I be jealous?” Kara asked, exasperated. Was she jealous? She didn’t know—but she pictured Alex having a romantic dinner with Maxwell Lord and her blood immediately turned to molten lava. “No way! You just deserve better than him. He can’t be trusted!” Fuming, she kept her head turned away, refusing to look into Alex’s eyes. Her beautiful, deep, loving eyes.

“It wasn’t a real date, Kara. It was purely for information gathering and a distraction—you know this.” Alex scooted closer on the couch, her warmth melting some of Kara’s anger. She reached around Kara and hugged her, kissing the back of her head. Waves of gentle tingling pleasure radiated out from where her lips touched Kara. Just like that, her remaining rage disappeared.

“Fine,” Kara said, still refusing to look her sister in the eye.

Confusion filled Kara as Alex pulled the hair away from the back of her neck and kissed her there, so softly, so affectionately it hurt.

Kara almost whimpered, her body desperately wanting more, but she maintained her dignity. She was going to leave it at that, get up and go to the restroom. Maybe go find Cat, and fuck her senseless until she passed out.

Kara was convinced Alex was merely showing sisterly love in a way that just happened to make Kara feel on the verge of strange, forbidden things—yes, she was clearly reading into it way too much.

But even pushing down every indecent thought didn’t prevent Kara’s cock from hardening, and with it an ache so intense she thought she might explode.

“Wow,” Alex said softly.

Wow what? Oh no, she didn’t notice the erection, did she?

Alex delicately placed a hand on Kara’s thigh and whispered in her ear, each word’s gentle flow of air sending wonderful chills up and down Kara’s spine.

“It’s okay to feel jealous, Kara, but you have nothing to worry about.”

Alex began massaging her thigh, first through her skirt but working her way down to Kara’s leggings, then back up her thigh again, lifting the skirt this time.

Needless to say, Kara’s cock was already at attention. Alex lifted her skirt the rest of the way, caressing her so wonderfully it was like agony. Forbidden bliss shot through Kara’s body like lightning as she continued to refuse thinking about all the naughty things she’d never, ever do to Alex.

“Oh fuck, Kara, I didn’t know it could get this big,” Alex whispered into her ear as her fingers worked their way further up Kara’s thigh, reaching her bulging cock.

A gasp escaped Kara’s lips as her mind swam through the confusion and overpowering lust. They shouldn’t be doing this, right? Was this even happening? Had she fallen asleep? Yes, it must be that—

But the burning ache behind her powerful erection felt all too real. Fuck, this was actually happening. Kara had fought against fantasies about Alex for years—she refused to embrace any hidden desires for her that lurked deep within. Sure, she was beautiful, but they shouldn’t do this kind of thing. Right? And yet… maybe, just maybe she could—no.

“Alex! What are you doing? I should go find Cat. I can go fuck her—that’ll help. I’m only horny because I haven’t gotten any lately, that’s all. I’ll be back in around half an—”

“Shh, it’s okay,” Alex whispered into her ear, rubbing Kara’s thick cock bulging out of her panties, already wet with so much precum she could feel it spilling out onto Alex’s hand. Alex kissed her neck again, making Kara moan as her tension eased. “You’re safe here. We’re just two sisters, expressing our love. That’s all it is. Besides, we aren’t blood-related… and I’m still hungry after that pizza, Kara.”

Fuck. This was happening. “I’ve got just the thing for you, then,” Kara said, pulling her cock out of her panties as adrenaline exploded inside her body, finally giving in to the overwhelming temptations her sister was offering.

Alex wrapped a hand around it, using her other to massage Kara’s shoulders. It felt so strange, so alien, letting her sister grab her cock like this. Alex began running her hand up and down the shaft, the precum serving as enough lubrication for her fingers to glide up and down its length.

Kara was Kryptonian, and Alex was human. Sure they were sisters, but they weren’t actually related. So it felt more than fine when Kara moaned and finally turned to face her loving sister, staring into her radiant pools, getting lost in them. Alex nodded soothingly and lowered her head.

Her lips parted around Kara’s cock, so delightful Kara couldn’t help but throw her head back and moan. Alex massaged her thighs as she worked her way down Kara’s lengthy shaft, the warmth of her mouth feeling hotter than the sun in that moment. Every touch Alex gifted her sent waves of pleasure dancing across her skin, relaxing her more than she thought possible, making her feel like everything was going to be okay.

Kara leaned back into the couch as ecstasy overtook her being, placing her hands behind her head as she watched in awe as Alex started to enthusiastically bob up and down the length of her shaft. Her skillful tongue and warm, loving, wet mouth delighted Kara in a comforting way she’d never experienced before. Kara smiled to herself as she imagined how overwhelmingly jealous Maxwell Lord would be if he saw Alex giving her this amazing blowjob.

Her cock twitched, almost ready to erupt, and Alex picked up her pace, reading Kara’s body language like nobody else could. She reached a hand up behind Kara, rubbing her back as she rapidly sucked down every inch of Kara’s cock, over and over, each time the tip bumping into the back of her throat.

Kara loudly moaned as she teetered on the brink of a powerful orgasm. “I’m coming, Alex!” she screamed, just as the head of her cock spasmed uncontrollably. Alex cradled Kara in the back of her mouth as thick loads of cum squirted down her throat. Kara’s hips involuntarily bucked, making Alex jump in shock, but she maintained her position, holding every inch of Kara inside her mouth, sucking down around the thick shaft, milking every drop Kara could offer her.

Lost in bliss and the amazing sight of Alex’s mouth around her cock, Kara stared on in stunned silence, not even a squeak escaping her gaping mouth.

Alex held her head there, even as Kara eventually stopped squirting down her throat, holding it there and moaning every single time Kara’s cock twitched. Finally, her cock finished after-orgasm spasming, and Alex lifted her head, licking her lips and smiling as Kara continued staring on in awe.

Kara couldn’t help it. As her mind was freed at last from the ecstasy that had overcome every part of her existence for a time, she grabbed Alex and pulled her in for a kiss. Her lips were so sweet and soft it hurt. Alex darted her tongue out, seeking to explore Kara’s mouth. Supergirl let her, tasting both herself and Alex mingling together. It was such a wonderful and sensuous kiss, Kara wasn’t sure if she wanted to laugh or cry or giggle or scream.

She pulled back, holding Alex’s shoulders, looking into her eyes as her lust began to mount once again, stronger than ever.

“Put on the dress you wore to dinner tonight,” Kara said. Her sister lifted her head, arching an eyebrow at Kara. She stared intently into Alex’s eyes, waiting expectantly for her to comply.

“Are you sure?” Alex asked.

“Of course. I’ll wait here,” Supergirl said, stroking her cock slowly with a firm grip, imagining what kind of dress it must have been. She was hard just from the thought, eager to see her sister but still feeling some leftover frustration that Maxwell Lord had seen her in the dress before Kara got to.

A few minutes later, Alex came walking back in, seductively approaching Kara. Did she always walk like that? Kara looked her up and down, admiring the curves underneath her snug black dress, her cleavage so tantalizing Kara wanted to fuck her tits on the spot. That fucker Maxwell Lord got to see her in this? Kara sneered, this time letting the jealousy flare up within her heart, blood pumping fast as renewed anger filled her chest.

Alex knew Kara all too well, it seemed. She got on her knees in the middle of the room and cupped her breasts, the low cut of her dress accentuating her bosom in a way that drove Kara wild with lust.

“There’s just you and me, Kara. Nobody else matters right now. Now come and titfuck me,” Alex said with a sexy grin.

“Fuck,” Kara whispered, beyond the point of no return, ready to fully give in to her desires to do forbidden things with Alex. She stood and ripped her skirt off, and as the fabric was loudly torn, Alex’s smile deepened.

Kara’s cock was still wet from Alex’s mouth, but as she moved into position, nestling her cock between her sister’s breasts, Alex drooled onto her shaft, lubricating it further. Kara thrusted, her massive rod filling the space between Alex’s tits, her cock bumping into her sister’s chin.

Alex let out the cutest yelp, and she giggled as Kara continued thrusting. She turned her face downward, opening her mouth, letting Kara slide up and down her chest and making an absolutely wet mess of her smooth skin. As Kara slid her cock up and down, the tip just reached Alex’s parted lips, and each time they met both women moaned.

An overpowering lust burned deeper and deeper within Kara, shaking her to the core. She abruptly stopped and gently set Alex down on her back against the floor. She grabbed the lovely black dress and ripped it wide open, all the way down to her waist.

“Kara!” Alex cried out as her body became a playground for her sister’s cock. Kara ran her length up Alex’s stomach, then up her chest, swirling the tip around each breast. Alex smiled up at her and held her tits up, inviting Kara to continue titfucking her without the dress getting in the way at all.

Supergirl eagerly obliged, lost in her lust as she thrusted. Her eyes swam all over Alex’s amazing body, taking in every sight, etching everything to memory. Kara quickly reached full speed, and the way Alex let her do this to her, the forbidden nature of everything happening, made Kara’s cock feel indescribably good.

“Maxwell Lord could never even dream of fucking your tits like this!” Kara screamed as she rocked her hips back and forth, enjoying the unbelievably smooth skin between her sister’s breasts and the drop dead sexy look on Alex’s face as she threw her head back and smiled.

“He’ll never get to lay a finger on me,” Alex reassured as Kara continued thrusting between her tits. “I don’t ever want to see his cock, but I know for a fact it could never compare to yours!”

Bliss shot through Kara’s cock at Alex’s words, and she screamed incomprehensibly, unable to properly warn her sister that she was about to erupt. Thick cum suddenly shot out as ecstasy shot through Kara’s cock. The first shot sprayed across Alex’s face, making her squeal in surprise with a huge, amused grin taking over her features. Load after load of Kara’s seed painted her sister’s neck and chest. Kara angled it around with each load, desperately wanting to mark every inch of her upper body. She covered both breasts in particular, panting heavily between moans as each load covering Alex’s body gave her an intense pleasure and deep sense of satisfaction. Kara gasped for breath as she finished, unable to take her eyes off of the beautiful sight before her.

Alex interrupted her thoughts with a tantalizing suggestion. “So, you’ve mentioned your fabled—prowess, let’s call it—a handful of times. If I were to tell you to fuck my pussy, how would that make you feel?”

Really fucking good! Well, she wanted to say that, but she decided to tone it down a bit, even as her cock hungered for more, desiring nothing else in the universe than to screw Alex any way she craved.

“Really fucking good!” Okay, maybe she couldn’t bare to tone it down after all. This was everything she never dared to admit she wanted, never letting her mind fully wander to this kind of fantasy. And now, it was a reality.

Alex spread her legs wide and Kara got into position without delay, rubbing her cock against her sister’s slit. It was sopping wet, surprising Kara with how ready Alex was for her to enter.

“I’m ready for you,” Alex whispered, staring at Kara with those dazzling eyes of hers.

Kara pressed forward, moaning alongside her sister as she slid smoothly in, using her strength to push further and further inside as Alex’s tight walls clamped down on her length. Her cock reached the end of her sister’s love tunnel, making Alex gasp. Kara gave in to every last desire, thrusting full speed ahead within a matter of seconds, rapidly pounding Alex into the floor, desperate to fill her to the brim with seed.

“Fuck! Oh, fuck, Kara!” Alex screamed as her insides were stretched and slammed into with superhuman speed.

Kara couldn’t speak, though she tried. All she could do was grunt and moan and scream as she drilled harder and faster, completely lost in her intense urges.

Alex’s pussy quaked around her cock, rocking Kara’s world, shaking her to the core. She held herself deep inside as another powerful orgasm washed over her, the sweetest bliss imaginable filling her heart with affection as she pumped her seed into Alex’s deepest reaches. Her tight pussy clamped down so tight as it quivered that Kara thought she might pass out from the intense pleasure.

As their bodies relaxed, Kara laid down on top of her sister. Alex wrapped her arms around Supergirl, warmly embracing her.

“We’re just two sisters, comforting each other in a messed up world,” Alex whispered as she ran her hands up and down Kara’s back.

Supergirl let herself drift off into a deep, relaxed slumber, not a care in the world as she slept in her sister's arms.


End file.
